assemblingbuffer.h

Linux下比较早的基于命令行的DVD播放器

//
// Copyright (c) 2003 by Istv醤 V醨adi
//
// This file is part of dxr3Player, a DVD player written specifically 
// for the DXR3 (aka Hollywood+) decoder card.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#ifndef DXR3PLAYER_ASSEMBLINGBUFFER_H
#define DXR3PLAYER_ASSEMBLINGBUFFER_H
//------------------------------------------------------------------------------

#include <cstdlib>

//------------------------------------------------------------------------------

/**
 * Buffer for data that is in several packets. The first 2 bytes
 * denote the total length of the data.
 */
class AssemblingBuffer
{
protected:
    /**
     * Get the length from the first two bytes of the given buffer.
     */
    static size_t getLength(const unsigned char* buffer);

protected:
    /**
     * The data buffer.
     */
    unsigned char* data;

    /**
     * The number of bytes added so far.
     */
    size_t addedBytes;

public:
    /**
     * Construct the object.
     */
    AssemblingBuffer();

    /**
     * Destroy the object.
     */
    ~AssemblingBuffer();

    /**
     * Add a certain amount of data from the given buffer.
     *
     * @return the number of bytes added.
     */
    size_t add(const unsigned char* source, size_t length);

    /**
     * Get the data.
     */
    const unsigned char* getData() const;

    /**
     * Get the length of the data.
     */
    size_t getLength() const;
    
    /**
     * Check if we have no data at all.
     */
    bool isEmpty() const;

    /**
     * Determine if we have all the data.
     */
    bool isFull() const;

    /**
     * Reset the assembling buffer, i.e. delete the current data, and make
     * it capable of receiving a new packetized data set.
     */
    void reset();
};

//------------------------------------------------------------------------------
// Inline definitions
//------------------------------------------------------------------------------

inline AssemblingBuffer::AssemblingBuffer() :
    data(0),
    addedBytes(0)
{
}

//------------------------------------------------------------------------------

inline AssemblingBuffer::~AssemblingBuffer()
{
    delete[] data;
}

//------------------------------------------------------------------------------

inline const unsigned char* AssemblingBuffer::getData() const
{
    return data;
}

//------------------------------------------------------------------------------

inline size_t AssemblingBuffer::getLength() const
{
    return (data==0) ? 0 : getLength(data);
}


//------------------------------------------------------------------------------

inline bool AssemblingBuffer::isEmpty() const
{
    return data==0;
}

//------------------------------------------------------------------------------

inline bool AssemblingBuffer::isFull() const
{
    return !isEmpty() && addedBytes==getLength();
}

//------------------------------------------------------------------------------
#endif // DXR3PLAYER_ASSEMBLINGBUFFER_H

// Local variables:
// mode: c++
// End: